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Vaccari L, Ranzi A, Canova C, Ghermandi G, Giannini S, Pitter G, Russo F, Stefanelli J, Teggi S, Vantini A, Jeddi M, Fletcher T, Colacci A. Reliability of toxicokinetic modelling for PFAS exposure assessment in contaminated water in northern Italy. Heliyon 2024; 10:e35288. [PMID: 39166031 PMCID: PMC11334853 DOI: 10.1016/j.heliyon.2024.e35288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/25/2024] [Accepted: 07/25/2024] [Indexed: 08/22/2024] Open
Abstract
Introduction Long-term contamination of tap water and groundwater by perfluoroalkyl and polyfluoroalkyl substances (PFASs) has been documented in the Veneto region of northern Italy. This study aimed to assess the exposure of individuals residing in the contaminated area and to test several toxicokinetic (TK) models of varying complexities to identify an efficient method for predicting perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) concentrations in human serum using observed data.The ultimate goal is to provide public health officials with guidance on selecting the appropriate TK model for specific contexts, a reliable and rapid tool to support human bio-monitoring (HBM) studies. Methods Two simpler empirical TK models and a more complex multi-compartment physiologically based toxicokinetic (PBTK) model were compared with individual and aggregate data from an HBM study. In addition, the PBPK model was modified by adjusting input parameters and introducing new terms into the equations within the original model code. These modifications aimed to optimize the results compared to the original model, with some versions incorporating adjustments to account for the influence of menstruation in women. All models were evaluated to understand their strengths and weaknesses, providing guidance on the appropriate model to use according to specific scenarios. Results The results obtained from the tested models were quite similar, with significant improvements observed only in the modified models. Simpler models also provided satisfactory results in scenarios involving low PFOS serum concentrations and recent exposure cessation. In many cases, predictions demonstrated high accuracy, particularly at the aggregate level and for women. Conclusions These findings suggest that environmental protection agencies and health authorities may benefit from employing the tested models at the aggregate level as an initial step in HBM studies, rather than conducting more invasive and expensive screening campaigns.
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Affiliation(s)
- L. Vaccari
- Center for Environment, Prevention and Health, Emilia-Romagna Regional Agency for Prevention, Environment and Energy (Arpae), 40139, Bologna, Italy
| | - A. Ranzi
- Center for Environment, Prevention and Health, Emilia-Romagna Regional Agency for Prevention, Environment and Energy (Arpae), 40139, Bologna, Italy
| | - C. Canova
- Unit of Biostatistics, Epidemiology and Public Health-University of Padua, Padua, Italy
| | - G. Ghermandi
- Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - S. Giannini
- Center for Environment, Prevention and Health, Emilia-Romagna Regional Agency for Prevention, Environment and Energy (Arpae), 40139, Bologna, Italy
| | - G. Pitter
- Screening and Health Impact Assessment Unit, Azienda Zero, Veneto Region, Padua, Italy
| | - F. Russo
- Directorate of Prevention, Food Safety and Veterinary Public Health, Veneto Region, Venice, Italy
| | - J. Stefanelli
- Agency for Prevention and Protection of the Environment of the Veneto Region (ARPAV), 35121, Padova, Italy
| | - S. Teggi
- Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, 41125, Modena, Italy
| | - A. Vantini
- Agency for Prevention and Protection of the Environment of the Veneto Region (ARPAV), 35121, Padova, Italy
| | - M.Z. Jeddi
- National Institute for Public Health and the Environment (RIVM), 3720 BA, Bilthoven, the Netherlands
| | - T. Fletcher
- London School of Hygiene and Tropical Medicine (LSHTM), London, UK
| | - A. Colacci
- Center for Environment, Prevention and Health, Emilia-Romagna Regional Agency for Prevention, Environment and Energy (Arpae), 40139, Bologna, Italy
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Akbaş KE, Hark BD. Evaluation of quantitative bias analysis in epidemiological research: A systematic review from 2010 to mid-2023. J Eval Clin Pract 2024. [PMID: 39031561 DOI: 10.1111/jep.14065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 05/17/2024] [Accepted: 06/03/2024] [Indexed: 07/22/2024]
Abstract
OBJECTIVE We aimed to demonstrate the use of quantitative bias analysis (QBA), which reveals the effects of systematic error, including confounding, misclassification and selection bias, on study results in epidemiological studies published in the period from 2010 to mid-23. METHOD The articles identified through a keyword search using Pubmed and Scopus were included in the study. The articles obtained from this search were eliminated according to the exclusion criteria, and the articles in which QBA analysis was applied were included in the detailed evaluation. RESULTS It can be said that the application of QBA analysis has gradually increased over the 13-year period. Accordingly, the number of articles in which simple is used as a method in QBA analysis is 9 (9.89%), the number of articles in which the multidimensional approach is used is 10 (10.99%), the number of articles in which the probabilistic approach is used is 60 (65.93%) and the number of articles in which the method is not specified is 12 (13.19%). The number of articles with misclassification bias model is 44 (48.35%), the number of articles with uncontrolled confounder(s) bias model is 32 (35.16%), the number of articles with selection bias model is 7 (7.69%) and the number of articles using more than one bias model is 8 (8.79%). Of the 49 (53.85%) articles in which the bias parameter source was specified, 19 (38.78%) used internal validation, 26 (53.06%) used external validation and 4 (8.16%) used educated guess, data constraints and hypothetical data. Probabilistic approach was used as a bias method in 60 (65.93%) of the articles, and mostly beta (8 [13.33%)], normal (9 [15.00%]) and uniform (8 [13.33%]) distributions were selected. CONCLUSION The application of QBA is rare in the literature but is increasing over time. Future researchers should include detailed analyzes such as QBA analysis to obtain inferences with higher evidence value, taking into account systematic errors.
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Affiliation(s)
- Kübra Elif Akbaş
- Department of Biostatistics and Medical Informatics, Faculty of Medicine, Fırat University, Elazig, Turkey
| | - Betül Dağoğlu Hark
- Department of Biostatistics and Medical Informatics, Faculty of Medicine, Fırat University, Elazig, Turkey
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3
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Niu S, Cao Y, Chen R, Bedi M, Sanders AP, Ducatman A, Ng C. A State-of-the-Science Review of Interactions of Per- and Polyfluoroalkyl Substances (PFAS) with Renal Transporters in Health and Disease: Implications for Population Variability in PFAS Toxicokinetics. ENVIRONMENTAL HEALTH PERSPECTIVES 2023; 131:76002. [PMID: 37418334 DOI: 10.1289/ehp11885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in the environment and have been shown to cause various adverse health impacts. In animals, sex- and species-specific differences in PFAS elimination half-lives have been linked to the activity of kidney transporters. However, PFAS molecular interactions with kidney transporters are still not fully understood. Moreover, the impact of kidney disease on PFAS elimination remains unclear. OBJECTIVES This state-of-the-science review integrated current knowledge to assess how changes in kidney function and transporter expression from health to disease could affect PFAS toxicokinetics and identified priority research gaps that should be addressed to advance knowledge. METHODS We searched for studies that measured PFAS uptake by kidney transporters, quantified transporter-level changes associated with kidney disease status, and developed PFAS pharmacokinetic models. We then used two databases to identify untested kidney transporters that have the potential for PFAS transport based on their endogenous substrates. Finally, we used an existing pharmacokinetic model for perfluorooctanoic acid (PFOA) in male rats to explore the influence of transporter expression levels, glomerular filtration rate (GFR), and serum albumin on serum half-lives. RESULTS The literature search identified nine human and eight rat kidney transporters that were previously investigated for their ability to transport PFAS, as well as seven human and three rat transporters that were confirmed to transport specific PFAS. We proposed a candidate list of seven untested kidney transporters with the potential for PFAS transport. Model results indicated PFOA toxicokinetics were more influenced by changes in GFR than in transporter expression. DISCUSSION Studies on additional transporters, particularly efflux transporters, and on more PFAS, especially current-use PFAS, are needed to better cover the role of transporters across the PFAS class. Remaining research gaps in transporter expression changes in specific kidney disease states could limit the effectiveness of risk assessment and prevent identification of vulnerable populations. https://doi.org/10.1289/EHP11885.
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Affiliation(s)
- Shan Niu
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Yuexin Cao
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Ruiwen Chen
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Megha Bedi
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alison P Sanders
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Alan Ducatman
- Department of Occupational and Environmental Health Sciences, West Virginia University, Morgantown, West Virginia, USA
| | - Carla Ng
- Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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4
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Liu M, Li A, Li Y, Zhang Q, Jiang G. Response to Comment on "Associations between Novel and Legacy Per- and Polyfluoroalkyl Substances in Human Serum and Thyroid Cancer: A Case and Healthy Population in Shandong Province, East China". ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:13512-13514. [PMID: 36048160 DOI: 10.1021/acs.est.2c05480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- Mei Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - An Li
- School of Public Health, University of Illinois at Chicago, Chicago, Illinois60612, United States
| | - Yingming Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Qinghua Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang310000, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing100085, China
- University of Chinese Academy of Sciences, Beijing100049, China
- School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, Zhejiang310000, China
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5
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Radke EG, Wright JM, Christensen K, Lin CJ, Goldstone AE, Lemeris C, Thayer KA. Epidemiology Evidence for Health Effects of 150 per- and Polyfluoroalkyl Substances: A Systematic Evidence Map. ENVIRONMENTAL HEALTH PERSPECTIVES 2022; 130:96003. [PMID: 36178797 PMCID: PMC9524599 DOI: 10.1289/ehp11185] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
BACKGROUND Per- and polyfluoroalkyl substances (PFAS) comprise a large class of chemicals with widespread use and persistence in the environment and in humans; however, most of the epidemiology research has focused on a small subset. OBJECTIVES The aim of this systematic evidence map (SEM) is to summarize the epidemiology evidence on approximately 150 lesser studied PFAS prioritized by the EPA for tiered toxicity testing, facilitating interpretation of those results as well as identification of priorities for risk assessment and data gaps for future research. METHODS The Populations, Exposure, Comparators, and Outcomes (PECO) criteria were intentionally broad to identify studies of any health effects in humans with information on associations with exposure to the identified PFAS. Systematic review methods were used to search for literature that was screened using machine-learning software and manual review. Studies meeting the PECO criteria underwent quantitative data extraction and evaluation for risk of bias and sensitivity using the Integrated Risk Information System approach. RESULTS 193 epidemiology studies were identified, which included information on 15 of the PFAS of interest. The most commonly studied health effect categories were metabolic (n=37), endocrine (n=30), cardiovascular (30), female reproductive (n=27), developmental (n=26), immune (n=22), nervous (n=21), male reproductive (n=14), cancer (n=12), and urinary (n=11) effects. In study evaluation, 120 (62%) studies were considered High/Medium confidence for at least one outcome. DISCUSSION Most of the PFAS in this SEM have little to no epidemiology data available to inform evaluation of potential health effects. Although exposure to the 15 PFAS that had data was fairly low in most studies, these less-studied PFAS may be used as replacements for "legacy" PFAS, leading to potentially greater exposure. It is impractical to generate epidemiology evidence to fill the existing gaps for all potentially relevant PFAS. This SEM highlights some of the important research gaps that currently exist. https://doi.org/10.1289/EHP11185.
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Affiliation(s)
- Elizabeth G. Radke
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Washington, District of Columbia, USA
| | - J. Michael Wright
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Krista Christensen
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Washington, District of Columbia, USA
| | | | | | | | - Kristina A. Thayer
- Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Durham, North Carolina, USA
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6
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Liu M, Zhang G, Meng L, Han X, Li Y, Shi Y, Li A, Turyk ME, Zhang Q, Jiang G. Associations between Novel and Legacy Per- and Polyfluoroalkyl Substances in Human Serum and Thyroid Cancer: A Case and Healthy Population in Shandong Province, East China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6144-6151. [PMID: 34618433 DOI: 10.1021/acs.est.1c02850] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs) are widely detected in the environment and may cause adverse human health effects after exposure. Studies on the effect of PFASs on some health end points, including cancer, are still limited and show inconsistent results. In this research, 319 participants were recruited from Shandong Province, East China, consisting of patients with thyroid cancer and healthy controls. Seven novel and legacy PFASs were frequently detected (detection rate > 75%) in the serum samples of the participants. The concentrations of perfluorooctanoic acid (PFOA) were the highest in the case and control groups. Males showed significantly higher concentrations of PFASs than females. Exposure to PFASs was inversely associated with the risk of thyroid cancer. In the control group, we identified significant positive associations between PFASs and free thyroxine (FT4) as well as between PFOA and thyroid stimulating hormone (TSH) in females. A significant negative association between perfluorononanoic acid (PFNA) and triiodothyronine (T3) was observed in males. Our results suggest that exposure to certain PFASs could interfere with thyroid function. To our knowledge, this is the first case-control study demonstrating associations between novel and legacy PFASs in human and thyroid cancer.
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Affiliation(s)
- Mei Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gaoxin Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Chemistry and Chemical Engineering, Northwest Normal University, Lan Zhou, Gansu 730070, China
| | - Lingling Meng
- Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan 250014, Shandong Province China
| | - Xu Han
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Research Institute of Petroleum Processing, Sinopec, Beijing 100083, China
| | - Yingming Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yali Shi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - An Li
- School of Public Health, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Mary E Turyk
- School of Public Health, University of Illinois at Chicago, Chicago, Illinois 60612, United States
| | - Qinghua Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Environment and Health, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Environment and Health, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310000, China
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7
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Li QQ, Liu JJ, Su F, Zhang YT, Wu LY, Chu C, Zhou Y, Shen X, Xiong S, Geiger SD, Qian ZM, McMillin SE, Dong GH, Zeng XW. Chlorinated Polyfluorinated Ether Sulfonates and Thyroid Hormone Levels in Adults: Isomers of C8 Health Project in China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:6152-6161. [PMID: 35380809 DOI: 10.1021/acs.est.1c03757] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Chlorinated polyfluorinated ether sulfonates (Cl-PFESAs) are one kind of replacement chemistry for perfluorooctanesulfonate (PFOS). Recent studies have shown that Cl-PFESAs could interfere with thyroid function in animal models. However, epidemiological evidence on the link between Cl-PFESAs and thyroid function remains scarce. In this study, we focused on two representative legacy perfluoroalkyl substances (PFAS), including PFOS and perfluorooctanoic acid (PFOA), and two PFOS alternatives (6:2 and 8:2 Cl-PFESAs) in the general adult population from a cross-sectional study, the "Isomers of C8 Health Project in China". Three serum thyroid hormones (THs), thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4), were measured. We fitted generalized linear regression, restricted cubic spline regression, and Bayesian kernel machine regression models to assess associations of individual Cl-PFESAs, legacy PFAS, and PFAS mixtures with THs, respectively. We found individual PFAS and their mixtures were nonlinearly associated with THs. The estimated changes of the TSH level (μIU/mL) at the 95th percentile of 6:2 Cl-PFESA and PFOS against the 5th percentile were -0.74 (95% CI: -0.94, -0.54) and -1.18 (95% CI: -1.37, -0.98), respectively. The present study provided epidemiological evidence for the association of 6:2 Cl-PFESA with thyroid hormone levels in the general adult population.
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Affiliation(s)
- Qing-Qing Li
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Jiao-Jiao Liu
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Fan Su
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Yun-Ting Zhang
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Lu-Yin Wu
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Chu Chu
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Yuanzhong Zhou
- Department of Epidemiology, School of Public Health, Zunyi Medical University, Zunyi 563060, China
| | - Xubo Shen
- Department of Epidemiology, School of Public Health, Zunyi Medical University, Zunyi 563060, China
| | - Shimin Xiong
- Department of Epidemiology, School of Public Health, Zunyi Medical University, Zunyi 563060, China
| | - Sarah Dee Geiger
- School of Nursing and Health Studies, Northern Illinois University, DeKalb, Illinois 60115, United States
| | - Zhengmin Min Qian
- Department of Epidemiology and Biostatistics, College for Public Health & Social Justice, Saint Louis University, St. Louis, Missouri 63104, United States
| | - Stephen Edward McMillin
- School of Social Work, College for Public Health and Social Justice, Saint Louis University, St. Louis, Missouri 63104, United States
| | - Guang-Hui Dong
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiao-Wen Zeng
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
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Andersen ME, Hagenbuch B, Apte U, Corton JC, Fletcher T, Lau C, Roth WL, Staels B, Vega GL, Clewell HJ, Longnecker MP. Why is elevation of serum cholesterol associated with exposure to perfluoroalkyl substances (PFAS) in humans? A workshop report on potential mechanisms. Toxicology 2021; 459:152845. [PMID: 34246716 PMCID: PMC9048712 DOI: 10.1016/j.tox.2021.152845] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/25/2021] [Accepted: 06/22/2021] [Indexed: 01/09/2023]
Abstract
Serum concentrations of cholesterol are positively correlated with exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) in humans. The associated change in cholesterol is small across a broad range of exposure to PFOA and PFOS. Animal studies generally have not indicated a mechanism that would account for the association in humans. The extent to which the relationship is causal is an open question. Nonetheless, the association is of particular importance because increased serum cholesterol has been considered as an endpoint to derive a point of departure in at least one recent risk assessment. To gain insight into potential mechanisms for the association, both causal and non-causal, an expert workshop was held Oct 31 and Nov 1, 2019 to discuss relevant data and propose new studies. In this report, we summarize the relevant background data, the discussion among the attendees, and their recommendations for further research.
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Affiliation(s)
| | - Bruno Hagenbuch
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd - MS 1018, Kansas City, KS 66160, USA.
| | - Udayan Apte
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd - MS 1018, Kansas City, KS 66160, USA.
| | - J Christopher Corton
- Advanced Experimental Toxicology Models Branch, Biomolecular and Computational Toxicology Division, Center for Computational Toxicology and Exposure, US Environmental Protection Agency, 109 T.W. Alexander Dr., MD B105-03, Research Triangle Park, NC 27711, USA.
| | - Tony Fletcher
- London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
| | - Christopher Lau
- Reproductive and Developmental Toxicology Branch, Public Health and Integrated Toxicology Division, Mail Code B105-04, Center for Public Health and Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
| | - William L Roth
- U.S. Food and Drug Administration (Retired), Numerical Animals, 16005 Frontier Rd., Reno, NV 89508, USA.
| | - Bart Staels
- Univ. Lille, Inserm, CHU de Lille, Institut Pasteur de Lille, U1011-EGID, F-59019 Lille, France.
| | - Gloria L Vega
- Center for Human Nutrition, Dallas, TX, USA; Department of Clinical Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390-9052, USA.
| | - Harvey J Clewell
- Ramboll US Consulting, Inc., 3214 Charles B. Root Wynd, Suite 130, Raleigh, NC 27612, USA.
| | - Matthew P Longnecker
- Ramboll US Consulting, Inc., 3214 Charles B. Root Wynd, Suite 130, Raleigh, NC 27612, USA.
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Andersen ME, Mallick P, Clewell HJ, Yoon M, Olsen GW, Longnecker MP. Using quantitative modeling tools to assess pharmacokinetic bias in epidemiological studies showing associations between biomarkers and health outcomes at low exposures. ENVIRONMENTAL RESEARCH 2021; 197:111183. [PMID: 33887277 DOI: 10.1016/j.envres.2021.111183] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Biomarkers of exposure can be measured at lower and lower levels due to advances in analytical chemistry. Using these sensitive methods, some epidemiology studies report associations between biomarkers and health outcomes at biomarker levels much below those associated with effects in animal studies. While some of these low exposure associations may arise from increased sensitivity of humans compared with animals or from species-specific responses, toxicology studies with drugs, commodity chemicals and consumer products have not generally indicated significantly greater sensitivity of humans compared with test animals for most health outcomes. In some cases, these associations may be indicative of pharmacokinetic (PK) bias, i.e., a situation where a confounding factor or the health outcome itself alters pharmacokinetic processes affecting biomarker levels. Quantitative assessment of PK bias combines PK modeling and statistical methods describing outcomes across large numbers of individuals in simulated populations. Here, we first provide background on the types of PK models that can be used for assessing biomarker levels in human population and then outline a process for considering PK bias in studies intended to assess associations between biomarkers and health outcomes at low levels of exposure. After providing this background, we work through published examples where these PK methods have been applied with several chemicals/chemical classes - polychlorinated biphenyls (PCBs), perfluoroalkyl substances (PFAS), polybrominated biphenyl ethers (PBDE) and phthalates - to assess the possibility of PK bias. Studies of the health effects of low levels of exposure will be improved by developing some confidence that PK bias did not play significant roles in the observed associations.
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10
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Petersen JM, Ranker LR, Barnard-Mayers R, MacLehose RF, Fox MP. A systematic review of quantitative bias analysis applied to epidemiological research. Int J Epidemiol 2021; 50:1708-1730. [PMID: 33880532 DOI: 10.1093/ije/dyab061] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Quantitative bias analysis (QBA) measures study errors in terms of direction, magnitude and uncertainty. This systematic review aimed to describe how QBA has been applied in epidemiological research in 2006-19. METHODS We searched PubMed for English peer-reviewed studies applying QBA to real-data applications. We also included studies citing selected sources or which were identified in a previous QBA review in pharmacoepidemiology. For each study, we extracted the rationale, methodology, bias-adjusted results and interpretation and assessed factors associated with reproducibility. RESULTS Of the 238 studies, the majority were embedded within papers whose main inferences were drawn from conventional approaches as secondary (sensitivity) analyses to quantity-specific biases (52%) or to assess the extent of bias required to shift the point estimate to the null (25%); 10% were standalone papers. The most common approach was probabilistic (57%). Misclassification was modelled in 57%, uncontrolled confounder(s) in 40% and selection bias in 17%. Most did not consider multiple biases or correlations between errors. When specified, bias parameters came from the literature (48%) more often than internal validation studies (29%). The majority (60%) of analyses resulted in >10% change from the conventional point estimate; however, most investigators (63%) did not alter their original interpretation. Degree of reproducibility related to inclusion of code, formulas, sensitivity analyses and supplementary materials, as well as the QBA rationale. CONCLUSIONS QBA applications were rare though increased over time. Future investigators should reference good practices and include details to promote transparency and to serve as a reference for other researchers.
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Affiliation(s)
- Julie M Petersen
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Lynsie R Ranker
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Ruby Barnard-Mayers
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Richard F MacLehose
- Division of Epidemiology and Community Health, University of Minnesota, School of Public Health, Minneapolis, MN, USA
| | - Matthew P Fox
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.,Department of Global Health, Boston University School of Public Health, Boston, MA, USA
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Dzierlenga MW, Allen BC, Clewell HJ, Longnecker MP. Pharmacokinetic bias analysis of an association between clinical thyroid disease and two perfluoroalkyl substances. ENVIRONMENT INTERNATIONAL 2020; 141:105784. [PMID: 32408218 DOI: 10.1016/j.envint.2020.105784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/06/2020] [Accepted: 04/30/2020] [Indexed: 06/11/2023]
Abstract
Exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) has been associated with the occurrence of thyroid disease in some epidemiologic studies. We hypothesized that in a specific epidemiologic study based on the National Health and Nutrition Examination Survey, the association of clinical thyroid disease with serum concentration of PFOA and PFOS was due to reverse causality. Thyroid hormone affects glomerular filtration, which in turn affects excretion of PFOA and PFOS. We evaluated this by linking a model of thyroid disease status over the lifetime to a physiologically based pharmacokinetic model of PFOA and PFOS. Using Monte Carlo methods, we simulated the target study population and analyzed the data using multivariable logistic regression. The target and simulated populations were similar with respect to age, estimated glomerular filtration rate, serum concentrations of PFOA and PFOS, and prevalence of clinical thyroid disease. The analysis showed little or no evidence of bias from the hypothesized mechanism. The largest bias was for the fourth quartile of PFOA in females, with an odds ratio of 0.93 (95% CI, 0.90, 0.97). The reported odds ratio of clinical thyroid disease for this group was 1.63 (1.07, 2.47), and if it were corrected for the bias would have been 1.74 (1.14, 2.65). Our results suggest that little of the reported association in the target study was due to reverse causality.
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